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Brains and Morals

Braintrust: What Neuroscience Tells Us About Morality by Patricia S. Churchland (Princeton University Press, hardback $27.20, paperback $18.24)

Reviewed by Charles Gibson

Braintrust What can science tell us about morality? In Braintrust, Patricia Churchland sets out to draw an up-to-date picture of our moral universe by applying philosophical analysis to the new and ever-growing body of scientific data emerging from advances in neuroscience, evolutionary biology and genetics. What, she asks, is the best interpretation of all this new evidence? Is morality an objective truth best expressed in terms of rules, or is it a social device that has developed in parallel to human evolution?

While this book contains a wealth of interesting information, Churchland doesn’t throw the reader in the deep end of neuroscience. She structures her book carefully to make it accessible to an everyday reader. This is one of Braintrust’s most notable achievements because presenting scientific evidence is not difficult. What is difficult is presenting it in a way that is both interesting and engaging to a wide audience, and Churchland makes it look easy, packing her book with fascinating tidbits about the natural world.

Added to this are the strong philosophical bookends in chapters one, seven and eight respectively, which set up the project and discuss alternative approaches to morality. This doesn’t mean that philosophy is absent from the rest of the book – Churchland discusses the implications and the best interpretations of the evidence as she goes – but these three chapters are by far the most purely philosophical.

The first of these bookends deals with some philosophical preliminaries before setting up the general structure of the book’s argument. Churchland’s opening move is to answer the question ‘How can science and philosophy go together?’ In pointing out that good philosophy starts out from a solid scientific basis, she aims to guard her book from accusations of ‘scientism’ – a term she uses for those who insist that science cannot or should not inform us about certain fields of research such as the nature of morality.

Braintrust suffers a little when dealing with these philosophical preliminaries. Churchland deals swiftly with some complex philosophical ideas, such as the is-ought gap, by which we cannot, with certainty, infer statements about what ought to be the case from statements about what is the case. Churchland accepts this gap, pointing out that an inference from ‘little boys are chimney sweeps’ to ‘little boys ought to be chimney sweeps’ is a very bad one. But here scientism rears its ugly head; science is built on observation and so generates ‘is’ facts. Morality on the other hand is full of ‘ought’ facts, so how can science inform us about morality?

Churchland deals with this problem by appealing to logic. She points out that the is-ought gap is only a problem for deductive logic simpliciter. Since her work is scientific, it primarily runs on inductive logic which uses a looser but more everyday notion of ‘infer’. She claims that this looser notion allows for just the kind of inference from facts to values that we need for science to inform us about morality.

This answer left me feeling a little unsatisfied. Churchland’s point is correct but deals too swiftly with a complex and potentially quite important question. Even when employing an everyday sense of infer, it is not obviously straightforward how much science can inform us about morality. While science is certainly full of observation and careful experimentation, it is very hard to observe or experiment on ‘ought’ facts. Don’t misunderstand me, I’m not endorsing scientism. Scientism is a foolish notion, and only the most irresponsible philosopher would ignore the vast wealth of information that science provides us with. My point is just that the first philosophical bookend of Braintrust misses an opportunity to set up the rest of the book in the strongest way possible. The science is excellent, but the philosophical support suffers because the discussions are not as robust as they could be.

The general structure of Churchland’s argument is a very interesting one. She offers a clear hypothesis before presenting her evidence for consideration. Her hypothesis is that what humans identify as morality is actually a complex system of social processes which evolved out of our instincts to protect ourselves, then our families, then our community and so forth. Churchland sets out the development of our modern notion of morality as having four dimensions to it: caring, recognition of others’ psychological states, problem solving in a social context and the learning of social practices.

Four Dimensions

In setting out the evidence for the caring dimension of moral development, Churchland paints a fascinating portrait of the role of neurochemicals in caring behaviour. Animals, including humans, which display highly social behaviour and /or strong nurturing tendencies all have high levels of oxytocin in their brain. Oxytocin is also responsible for producing endogenous opiates during suckling. Give naloxone, a chemical which blocks the reception of these opiates, to a rhesus monkey and it will tend to neglect its young. Administer oxytocin via nasal spray to participants in a study on trust and they will be far more trusting than the group given a placebo nasal spray. It is in fact this powerful chemical which extends our survival instincts from us to our offspring, to our kin, and finally to our community.

The hypothesis Churchland is arguing for here is that one source of our modern notion of morality is a long and slow process of ‘caring extension’. Life is motivated to preserve its genetic material, so we have a natural instinct to care about ourselves. Because our genetic material can only be preserved through offspring, we develop a caring instinct for our children, which is amplified by oxytocin. Oxytocin then extends our caring to our family and out to our community. As we co-operate more we gain a better chance of survival and so the number of oxytocin sensitive offspring increases. Over long periods of time this develops into a strong sense of empathy which extends our caring instincts to complete strangers and even in some cases our enemies.

This hypothesis is well supported by the evidence Churchland presents but it does not tell the whole story of morality. Motivations of caring and a priority towards offspring are very good at explaining why humans have a collective aversion to violence against children, but are less successful at explaining why we think it is wrong to intentionally give a complete stranger incorrect change for a purchase. This is where Churchland’s second dimension comes into play. As co-operation increases, we need a set of tools to navigate trading and other co-operative enterprises. This is supplied by the ability to accurately predict the psychological states of the people we are co-operating with.

The ability to accurately recognise the psychological states of people influences how successful we are at bartering and thus our own fitness for survival. Oxytocin again plays a strong role here; large amounts of it make us better at reading other humans’ emotions. The humans who were more successful at accurately gauging the psychological states of others had an evolutionary advantage and thus a better chance of survival and reproduction. Over time these basic features develop into general rules for navigating the world; ‘you ought not (in the sense of it’s ill-advised) go around making people unhappy for no reason’. Until it slowly changes into a moral claim; ‘it’s wrong to go around making people unhappy for no reason’.

This aspect leads nicely into Churchland’s third dimension of moral development; problem solving in a social context. Put a plate of food on a platform in a cage which can only be retrieved by pulling two different ropes simultaneously and chimpanzees will work together to retrieve the food. Being forced to work together yields a benefit for us which quickly instils the idea that it is something we should do. Over generations, we develop a sophisticated set of ought statements to deal with a plethora of social problems from the survival of the whole community to when we ought to compliment our friends on their work.

But here the evolutionary story gets interesting. The same chimpanzees work far better together when their partner chimp is of equal social status. A lower caste chimp is less likely to cooperate with a more dominant chimp since he could take the majority of the food for himself. This suggests that while morality leads to the notion of working together, there is always some presence of self-benefit influencing our behaviour. It just happens that because working together tends to benefit us individually in the long run, it increases our chance of survival, and the tendency for it is preserved over generations.

Churchland’s fourth dimension does two important things. Firstly it nicely ties together the other three dimensions. Secondly it provides an explanation for why humans feel so strongly about moral issues. As children we are rewarded for doing the ‘right’ thing and punished for doing the ‘wrong’ thing. So we absorb a notion of what we ought or ought not to do. Through conditioning, we form associations between displeasure and ‘wrong’ behaviours, thus as we grow we develop a conscience. This completes a convincing evolutionary tale backed up by solid scientific evidence. If Churchland’s theory is the correct theory of morality then it must be able to explain not just where morals came from but why people are so intuitively convinced that there are objective facts about whether abortion is wrong. Churchland’s fourth dimension explains this psychological fact nicely and to the author’s credit, she is careful to point out her hypothesis is part of the story of morality rather than the whole story.

Moral Rules
After laying out a fascinating collection of evidence, Churchland moves to the second philosophical bookend of Braintrust. In this section she considers and rejects rule-based and religious approaches to ethics. Like the first philosophical bookend, it is interesting but deals far too swiftly with complex philosophical problems. Churchland is right to be sceptical about rule-based approaches such as utilitarianism. One thing that they struggle to account for is the wide moral diversity between cultures, something that we are indebted to scientists for taking the time to document so carefully. However 30 pages is just not enough space to comprehensively refute consequentialism, Kant, and the naturalistic fallacy. The debates over these ethical theories have become increasingly complicated and are on-going.

The other weakness of this bookend is that Churchland does not devote enough space to considering objections to her theory. While she does discuss alternative explanations of morality, she spends the majority of the space attacking those theories rather than defending her own. This is a problem because Churchland’s explanation of morality seems at times to approach moral relativism. (This is the idea that there is no objective account of morality, just what a society approves or disapproves of.) While these types of theories are seductive, they have the catastrophic implication that we cannot perform moral judgement. We cannot say anymore that the Holocaust was wrong, just that it conflicted with our cultural practices of ‘not performing genocide’.

Churchland’s theory is vulnerable to a similar objection. The sentence ‘genocide is wrong’ is no longer true because there is something extremely wrong about genocide. Instead ‘right’ means the typical behaviours among human beings which were preserved through a long process of evolution. On the most charitable interpretation, ‘genocide is wrong’ expresses the notion that we ought not to engage in genocide because it decreases our fitness for survival as a species. But this fact is surely not what makes genocide wrong.

Churchland does briefly sketch out a response to this objection. She claims that morality is real because it is rooted firmly in evolutionary biology, thus “it is as real as social behaviour”. But this response is again too swift and fails to answer the original objection. Moral objectivists are not debating whether genocide occurs or people disapprove of genocide occurring. They are arguing that if morality is just an evolutionary side effect then there is no objective justification for the condemnation of genocide. Churchland, to my mind, has not yet answered this objection. This does not make Braintrust a bad book. Braintrust is an excellent book. Unfortunately though, it lacks the kind of robust philosophical discussion that would make it a superb book.

To the author’s credit, Braintrust accomplishes something rare; it makes a dense and complicated subject interesting and accessible. It sets the bar very high for itself and accomplishes most, if not all, that the author intends for it. It would be a delight to see Churchland play around with more philosophy as her ideas are compelling, well supported by the evidence, and set the stage for some very interesting philosophical discussion. But this is an afterthought. Braintrust is a fascinating book and if you are interested in finding out what modern science can tell you about morality then pick up a copy. It will be money well spent.

Charles Gibson is a postgraduate student at the University of Otago, New Zealand. He is currently researching a Master’s project on ethical issues in digital piracy. His primary research interests are logic, philosophy of science and ethics. In his spare time he enjoys digital entertainment and gathers philosophical examples from pop culture to aid in tutoring.